This invention relates to a conformable insulation assembly which is used to insulate buildings and, for example to insulate floors, ceilings, walls and the like of such buildings.
It is well known in the art to insulate buildings using various types of insulating materials including mineral fibers such as fibrous glass wool.
The common prior art methods for producing glass fiber insulation products involve producing glass fibers from a rotary fiberizing process. A single molten glass composition is forced through the orifices in the outer wall of a centrifuge or spinner, producing primarily straight, short glass fibers. The fibers are drawn downward by a blower. The binder required to bond the fibers into a wool product is sprayed onto the fibers as they are drawn downward. The fibers fall downward onto a conveyor. The fibers are collected in generally horizontal layers on the conveyor as they fall forming a wool pack. The wool pack is further processed into insulation products by heating in an oven, and mechanically shaping and cutting the wool pack, for example, into a rectangle.
Prior art glass wool blankets are generally rectangular, horizontally layered and substantially rigid in nature. As previously stated, they often include a binder, such as a phenolic resin, added to the glass wool subsequent to the fiberizing process. The resultant insulating material has sufficient strength and rigidity to be employed as insulating blankets in walls, floors and ceilings.
However, prior art glass wool blankets, due to their rectangular shape, use of primarily short fibers and rigid nature have no ability to conform to the spaces of a building into which they are installed. That is, building construction inevitably contains abnormal voids, for example, spaces created between floor, wall, and ceiling joists, as a part of the framing construction or non-uniformly shaped barriers such as electrical wiring, boxes and plumbing. Existing insulation blankets, being generally rectangular, composed of primarily short fibers and substantially rigid, are unable to conform to and fill these abnormal voids. As a result, the effectiveness of the insulation is diminished when gaps and abnormal voids are present. Alternatively, the installer must cut the insulation to fit into the voids, increasing the time required to do the project. Further, some existing insulation blankets for attics are designed to fit between the spacings of support timbers or joists. Thus, a gap corresponding to the width of the support timber or joist is left between neighboring insulation blankets. These gaps also reduce the blankets effectiveness as well as provide an unsatisfactory appearance.
In addition, in the production of wool insulating materials of glass fibers, it becomes necessary to use fibers that are relatively short to achieve desired lattice properties. Long fibers tend to become entangled with each other, forming ropes, strings or more wispy entanglements. The aerodynamic properties of long fibers make them difficult to distribute, and conventional lapping techniques are largely ineffective in handling long fibers. The ropes of long fibers produce a commercially undesirable appearance and reduce the insulating abilities of the glass wool by causing a non-uniform distribution of the glass fibers in the insulation product.
A further problem presented by the use of short straight fibers is the binder material which must necessarily be added to the fibers to provide product integrity. Binder provides bonding at the fiber to fiber intersections in the insulation blanket lattice. However, binders are expensive and have several environmental drawbacks. As most binders include organic compounds, great pains must be taken to process effluent from the production process to ameliorate the negative environmental impact. Further, the binder must be cured with an oven using additional energy and creating additional environmental cleanup costs. While long fibers display some fiber to fiber entanglement, even without binder, the non-uniformity of the resulting wool packs has long made them commercially undesirable.
Non-wool insulation products, such as loose fill, are also known. These loose fill products are conformable in the sense that they have no preordained shape. Loose fill is merely individual groups of insulation fibers. The insulation is generally installed by blowing into the area to be insulated. However, the insulation is difficult to handle, requires special equipment to install and due to its installation technique and loose nature, loose fill commonly has airborne particles, is irritable to the skin and without the appropriate care being taken can leave gaps and voids when blown into the cavity. Further, loose fill insulation cannot be handled as a unit, similar to an insulation batt.
Recently, binderless wool insulation products have been developed. U.S. Pat. No. 5,277,955 to Schelhorn et al. discloses a binderless insulation assembly. The insulation assembly comprises a mineral fiber batt, such as glass fibers, enclosed within an exterior plastic covering. Binder is not required. A layer of adhesive holds the plastic cover to the fiber batt. However, the insulation assembly of Schelhorn et al. is not generally capable of conforming to the voids in construction spaces or filling the gaps between blankets because the fiber batt is made of primarily straight, short glass fibers, and the batt is formed into a rectangle or cross-section by cutting the fibers prior to enclosing the batt in the plastic cover.
Accordingly, the need remains for a conformable wool insulation assembly which conforms to abnormal voids in building spaces, is relatively easy to install, and does not have the drawbacks of loose fill insulation.